1. Field of the Invention
This invention relates to a liquid thermal accumulator composition and a process for accumulation of thermal energy utilizing said liquid composition. More particularly, this invention relates to a liquid thermal accumulator composition for accumulating therein thermal energy in the form of chemical energy and a thermal accumulation process utilizing the same.
2. Description of Prior Arts
A variety of thermal accumulation processes, namely, processes for accumulation of thermal energy, are heretofore known. The known processes can be classified into various processes, for instance, a process of accumulation of thermal energy in a medium in the form of sensible heat such as a process using an oily medium; a process of accumulation of thermal energy in a medium in the form of latent heat such as a process using paraffin; and a process of accumulation of thermal energy in the form of chemical energy such as a process employing ammonia. Among these processes, the process of accumulation of heat energy in the form of chemical energy, namely chemical heat-accumulation process, is very favorable in practice, because it is high in the density of thermal energy accumulation and is free from escape of thermal energy in the storage, whereby it is capable of keeping the thermal energy for a long period of time with almost no heat loss.
Heretofore, the chemical heat-accumulation process has been studied mainly on processes in which production of gas by thermal decomposition of a solid inorganic material is involved. In more detail, previously the study of the chemical heat-accumulation process has been made mainly for utilizing reaction systems which comprise production of gas such as steam, carbon dioxide, ammonia or hydrogen.
However, the chemical heat-accumulation processes involving production of gas from a solid material have drawbacks in that:
(1) a heat source of a high temperature is required to accumulate thermal energy;
(2) it is difficult to stably operate the involved heat accumulation cycle for a long period of time;
(3) there is a problem in thermal conductivity because the solid-gas composition system is involved;
(4) apparatus of a large size is required; and
(5) the apparatus is apt to be corroded.
Chemical heat-accumulation processes using organic materials have been also studied. Most of these studies have been made on chemical reaction systems likewise involving production of gas. Therefore, these processes are likewise not free from the drawbacks described above.